1. Field of the Invention
The present invention relates generally to an improved data processing system, and in particular, to a computer implemented method for multipath data communications. Still more particularly, the present invention relates to a computer implemented method, system, and computer usable program code for energy conservation in multipath data communications.
2. Description of the Related Art
Data processing systems can be divided into logical partitions (LPAR). A logical partition is also known simply as a “partition”. Each partition operates as a separate data processing system independent of the other partitions. Generally, a partition management firmware connects the various partitions and provides the network connectivity among them. Hypervisor is an example of such partition management firmware.
A partition may access one or more data storage devices for reading, writing, storing, and managing data. In some partitioned data processing systems, virtual input/output (I/O) servers provide the partitions access to one or more data storage devices. A data storage device may include one or more physical data storage units, such as hard disks, as in the case of a storage array, or a storage area network (SAN).
A partition, with or without the use of a virtual I/O server may access a particular data storage device over more than one data communication paths. Data communications conducted between a partition and a data storage device over more than one data communication paths are called multipath input/output (multipath I/O).
A partition utilizing multipath I/O may use multiple I/O adapters to communicate with the data storage device. Each I/O adapter communicates with the data storage device over a separate data network. Multipath I/O configurations are commonly employed in partitioned data processing system for increasing the data throughput rates between a partition and a data storage device. Multipath I/O configurations also improve the reliability of the data communications between a partition and a data storage device by providing redundant data communication paths between them.